Peas are native to the Mediterranean and Central Asia. They are now one of the world's important cultivated crops, mainly distributed in Asia and Europe.
1. Pea planting conditions
① Temperature
Peas are semi-cold-resistant crops. They like wet and humid climates and are not resistant to dryness, heat and monotony. Round-grain peas are more cold-resistant than wrinkled-grain peas. The starting temperature for seed germination is lower, 1-2℃ for round-grain peas and 3-5℃ for wrinkled-grain peas. However, seeds germinate slowly at low temperatures.
The seedlings are more cold-resistant, and the suitable temperature for the seedling stage is 15-20℃. The minimum temperature for flowering is 8-12℃. The most suitable temperature for flowering and pod formation is 15-18℃. The pod maturity stage requires 18-20℃. When the temperature is high and drought, the pods mature prematurely, and the yield and quality decrease.
②Water
Pea is a warm-loving crop. Its drought resistance is not as good as other vegetables such as beans and cowpeas. During the growth period, the air humidity is about 75%, and the relative water content of the soil is about 70%. The plant grows well, but peas are not resistant to rain and waterlogging. During the growth period, it is rainy and cloudy, and it is prone to a variety of diseases. Pea seedlings can tolerate drought. It needs more water during the flowering and pod-setting period. The relative humidity of the air should be 60%-80%. Too high or too low will seriously affect flowering and pod-setting.
③Soil
Pea has a wide adaptability to soil and does not require high soil quality. Sandy loam and loam with strong water retention, good ventilation and rich in humus are the most suitable. The optimal soil pH is 6.0-7.2. For soils with excessive acidity, lime can be added to the soil to improve it.
④Nutrients
Peas have a large demand for phosphorus and potassium fertilizers. The peak period of phosphorus demand is reached 15-16 days after flowering. When phosphorus is insufficient, the plant is short, the leaves are small and dull, and the flowers are few. Potassium has the effect of strengthening the stalks and resisting lodging. The peak of potassium demand is reached 31-33 days after flowering. It is more sensitive to the trace elements boron and molybdenum. 0.3%-0.5% borax or 0.01%-0.05% ammonium molybdate can be sprayed to make up for the deficiency.
2. Pea sowing method
① Seed selection and germination
Before sowing, select seeds with 40% salt water and remove seeds that float and are not full or damaged by insects. Germinate the seeds before sowing. When the seeds sprout, treat the seeds at a low temperature of 0-2℃ for 15 days before sowing.
② Rhizobium seed dressing
Mixed pea seeds with rhizobium is an effective measure to increase production. After mixing seeds with rhizobium, the nodules increase, the stems and leaves grow vigorously, the pods are more, and the yield is high. The seed mixing method is to use 10-19 grams of rhizobia per mu, add a little water and mix with the seeds before sowing.
③ Timely sowing
Before field sowing, apply fully rotten manure, compost and a certain amount of phosphorus and potassium fertilizers, especially phosphorus fertilizer, which has a significant effect on increasing yield. Peas are sown in spots, with a row spacing of 10-20 cm and a plant spacing of 5 cm in the row. Sow 2-6 seeds in each hole, and cover the soil with 5-6 cm when the soil is moist. When the soil is dry, cover the soil a little thicker. Use 10-15 kg of seeds per mu.
3. Pea planting technology
① Cultivation requirements
Peas should not be planted continuously. After continuous planting, it can cause toxic effects on the subsequent peas and aggravate the occurrence of diseases and pests. Therefore, peas are usually rotated with other crops. White flower varieties are more afraid of continuous planting than purple flower varieties, and their rotation period needs to be longer. Peas can also be mixed and intercropped with other crops.
② Land selection
Drip irrigation cultivation has low soil requirements, which is conducive to seedling survival and crop growth. Therefore, it can be planted in land with deep soil layer, low soil salinity and medium fertility.
③ Loosening soil and fertilizing
After sowing, the soil should be loosened several times to increase the ground temperature, promote root growth and make the seedlings strong.
Before peas bloom, water them with small amounts of fast-acting nitrogen fertilizer to accelerate plant growth and promote branching, and then loosen the soil to retain moisture. When the stems begin to set pods, increase the amount of watering slightly and apply phosphorus and potassium fertilizers. The soil should be kept moist at all times during the peak pod-setting period. Ensure the water required for pod development. In the late stage of pod-setting, the bean seedlings are sealed with ridges and watering is reduced.
When the vine-growing plants are 30 cm tall, start supporting. Peas are harvested in batches, and fertilizer is applied once every harvest.
④ Filling gaps and applying fertilizer
After the seedlings emerge, check the seedlings and fill gaps in time, and weed 1 to 2 times. Apply heavy topdressing during the seedling stage, especially for fields where no or little basal fertilizer is applied. Generally, 5-7.5 kg of compound fertilizer or 5 kg of urea should be applied per mu.
When the temperature rises and the plants of tall stalks begin to elongate, insert small bamboos with tips or branches (without leaves) between the rows so that the bean plants can climb and grow.
More nutrients are needed during flowering and pod formation. Apply 7.5 kg of urea and 5 kg of triple compound fertilizer per mu. Spray 1% urea and 0.3% potassium dihydrogen phosphate twice during the grain filling stage.
⑤ Disease and pest control
The main diseases of peas are root rot, brown spot disease, powdery mildew, brown streak disease, etc. The main pests are black miner, leaf miner, etc.
⑥ Timely harvest
Determine the harvest time according to the way of consumption. Generally, grain peas are harvested when the grains are full 15 to 18 days after flowering, dry peas are harvested when 70% to 80% of the pods are withered and yellow, vegetable peas are harvested 12 to 14 days after flowering when the young pods show seeds but not grains, and pea seedlings are harvested when the top shoots are 18 cm tall about 30 days after sowing. Peas used as feed are harvested during the peak flowering period, and those used as green manure are turned over in time after the pods are harvested.
